For most Plebes it is not that they are not capable of doing the work and the Plebe training, they just don't know how to do it.
Most do not have good study skills. Most skated through HS. Most did not have to study in HS. Most did not study their SR. year of HS. Add that all up and you have a Plebe that will struggle. They will study all of the time and learn nothing because they never learned how to study in the first place.
Now before everyone jumps on me and says our high school was very competitive, our high school had top scholars, our HS hat top SAT/ACT scores - that may be but I would lay money that your plebe never learned how to study - what they learned was how to get a good grade at their high school. I saw this over and over when I tutored.
One thing to ask your Plebes Where are you studying? If they reply in the Hall, that is a huge mistake - way too many distractions! They need to get in the habit of going to the Library. Tend to business from 7:30 to 10pm and then go back to the hall. What are they doing when not in Class - that is the time to do homework. Your Plebes need to get their home work done during the day so they can study in the evening. Go to class prepared for that day's lecture - studying - having the next day's lesson looked at so that you can follow in class. That in itself will make a huge difference. Just doing the home work will not be enough.
USNA1985 is so right. Those that are studying "all the time" are so inefficient and ineffective that they will be unsat all of the time and then the vicious cycle repeats...
Validating to a higher level of class is an excuse. They proved on the validation test that they were ready for the next class. Again most that I know that purposely did not validate so they could have an "easier" Plebe year - ended up doing poorly because they had the attitude that they already knew this stuff so they didn't need to study.
Plebes in my Platoon last fall also spent a good bit of the first 2 to 4 weeks thinking it was "all a review" and got off to a poor start. Huge mistake! One that is very hard overcome.